Getting a hot tub. Questions about my deck...

[brokenknee]

load calculation web site

Maximum Floor Joists Span

 

[Steppenwolfe]

DO NOT put that hot tub on that deck, yet... When it comes to hot tubs on a deck, you CAN NOT over build. Double up the existing joists and add a single in between. Beef up the perimeter beam would be nice. One thing to know, lag bolts are not code. They must be through bolts, "carriage bolts", with a washer and nut on the inside of your house ledger. The number one failure for decks is due to in proper fastening to the house. Also, screw those joist hangers, not nailed.

 

[Billrog]

The outer fting.the posts are on looks good & solid. Make sure the rim joist at the house is well lagged or bolt through if practical to do so. Put new joist @12" centers And double up the center 2 under the tub. Buy heavy hangers and do not use screws use proper nails made for hangers.

 

[williaty]

After many years, I'm finally giving in to SWMBO and agreed to a hot tub. Not getting a big one - just a two seater. You can see it here.

Mind sharing what you're paying? That's just about what my wife and I are looking for and I don't want to give them all my info just to get a ballpark price out of them.

 

[bcp]

Proper hanger nails vs proper hanger screws?

Strong-Drive® SD Structural-Connector Screw

Bruce

 

[kenmac]

Mind sharing what you're paying? That's just about what my wife and I are looking for and I don't want to give them all my info just to get a ballpark price out of them.

I bought my 6-8 person for 2k used ..It was about 6-7 K new.. You can buy used for a fraction of new from someone after the new wears off..

I've had it for 4 yrs and had to replace the heating element last yr

 

[davesl708]

The thing to remember is the tub is dead weight on the deck. A relentless pressure pushing down.
If additional support post under the tub area is not feasible then double the floor joist. Add a more lags into the house frame. You may end up with 6 - 8 people or more on the deck as well as the tub. This would not be a good place to just meet the minimum load requirements.

By the way, mine gets used almost every day. Soak a half hour before bedtime and sleep like Rip Van Winkle.

 

[williaty]

I bought my 6-8 person for 2k used ..It was about 6-7 K new.. You can buy used for a fraction of new from someone after the new wears off..

I've had it for 4 yrs and had to replace the heating element last yr

The problem is that only the big ones come up used. That's why we don't have one yet. I've been looking for a long time for one as small as what the OP is showing.

 

[s219]

DO NOT put that hot tub on that deck, yet... When it comes to hot tubs on a deck, you CAN NOT over build. Double up the existing joists and add a single in between. Beef up the perimeter beam would be nice. One thing to know, lag bolts are not code. They must be through bolts, "carriage bolts", with a washer and nut on the inside of your house ledger. The number one failure for decks is due to in proper fastening to the house. Also, screw those joist hangers, not nailed.

Agree about the lags being bad. Not sure if the OP has access from that lower level to see if through bolts and nuts with washers were used, but that would certainly ease my mind.

Carriage bolts are not to code here in my county in VA -- must use a standard bolt with washer under the head. Heard it's a combination of carriage bolts not having proper structural ratings, and need for a washer.

And for decks, new code requires structural brackets that actually tie the deck joists into the building framing. Simpson makes a bracket that screws on to the side of deck joists, and then threaded rod runs from that, through the rim, and into the building's framing -- tying into the interior joists (blocking can be used to help line them up). We have those about every 2-3 joists on my front porch framing. Really ensures that the joists are going to be held to the building. Here's a typical setup:



One thing I noticed in the OP's photos is that the joist hangers seem "short", as if they are for smaller lumber. Not very many nails supporting each joist there (roughly figure on a nail being good for 100-140# shear load in typical framing lumber, unless you know otherwise). I'd suggest replacing with full length hangers and make sure the attachment is good. Would either use nails or structural screws (that have known shear rating). Typical deck screws do not have shear ratings or good shear performance -- they are only for tension loads.

 

[sld]

I use these things quite a bit. They really sink in and bite without a pilot hole. Amazing fastener actually. They come in a bunch of different sizes too.

SPAX 5/16 in. x 4 in. External Hex Flange Hex-Head Lag Screw-4571820801007 - The Home Depot